Methodology of live cell microcalorimetry experiments.

The method by which cells are grown, seeded, and analyzed for their heat generation from the microcalorimeter is shown. First, E. coli BW25113 single-gene knockout cells (green), E. coli BW25113 wild-type (gray), and a negative control of media are seeded for overnight culture. Then, cells are inoculated at an initial OD600 value of 0.005 in a 20 mL glass ampoule. Ampoules are sealed and lowered into the microcalorimeter using ddH2O as the negative control. After 5 h, the cells are removed from the microcalorimeter, and the final OD600 value is measured. The sample heat flow curves are analyzed for the peak value (qpeak). This value is normalized by the final OD600 value to get a growth-normalized heat flow measurement.